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+Deterministic Inputs
+====================
+
+We are aiming to make the compilers ultimately deterministic (https://github.com/dotnet/roslyn/issues/372). What that means is that the "same inputs" will cause the compilers to produce the "same outputs". 
+
+The following will be considered inputs to the compiler for the purpose of determinism:
+
+- The sequence of command-line flags
+- The contents of the compiler's `.rsp` response file.
+- The precise version of the compiler used, and its referenced assemblies
+- Current full directory path (you can reduce this to a relative path; see https://github.com/dotnet/roslyn/issues/949)
+- (Binary) contents of all files explicitly passed to the compiler, directly or indirectly, including
+  - source files
+  - referenced assemblies
+  - referenced modules
+  - resources
+  - the strong name key file
+  - `@` response files
+  - Analyzers
+  - Rulesets
+- The current culture
+- The default encoding (or the current code page) if the encoding is not specified
+- The existence, non-existence, and contents of files on the compiler's search paths (specified, e.g. by `/lib` or `/recurse`)
+- The CLR platform on which the compiler is run (e.g. the result of `double` arithmetic performed for constant-folding may use excess precision on some platforms).
+
+At the moment the compiler also depends on the time of day and random numbers for GUIDs, so it is not deterministic unless you specify `/features:deterministic`.